gen/FreeBSD/getlogin.c

   1 /*
   2  * Copyright (c) 1988, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static char sccsid[] = "@(#)getlogin.c  8.1 (Berkeley) 6/4/93";
  32 #endif /* LIBC_SCCS and not lint */
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD: src/lib/libc/gen/getlogin.c,v 1.11 2009/12/05 19:04:21 ed Exp $");
  35
  36 #include <sys/param.h>
  37 #include <errno.h>
  38 #include <pwd.h>
  39 #include <stdio.h>
  40 #include <string.h>
  41 #include <unistd.h>
  42 #include "namespace.h"
  43 #include <pthread.h>
  44 #include "un-namespace.h"
  45
  46 #include "libc_private.h"
  47
  48 #define THREAD_LOCK()   if (__isthreaded) _pthread_mutex_lock(&logname_mutex)
  49 #define THREAD_UNLOCK() if (__isthreaded) _pthread_mutex_unlock(&logname_mutex)
  50
  51 extern int              __getlogin(char *, int);
  52
  53 int                     _logname_valid;         /* known to setlogin() */
  54 static pthread_mutex_t  logname_mutex = PTHREAD_MUTEX_INITIALIZER;
  55
  56 static char *
  57 getlogin_basic(int *status)
  58 {
  59         static char logname[MAXLOGNAME];
  60
  61         if (_logname_valid == 0) {
  62                 if (__getlogin(logname, sizeof(logname)) < 0) {
  63                         *status = errno;
  64                         return (NULL);
  65                 }
  66                 _logname_valid = 1;
  67         }
  68         *status = 0;
  69         return (*logname ? logname : NULL);
  70 }
  71
  72 char *
  73 getlogin(void)
  74 {
  75         char    *result;
  76         int     status;
  77
  78         THREAD_LOCK();
  79         result = getlogin_basic(&status);
  80         THREAD_UNLOCK();
  81         return (result);
  82 }
  83
  84 int
  85 getlogin_r(char *logname, size_t namelen)
  86 {
  87         char    *result;
  88         int     len;
  89         int     status;
  90
  91         THREAD_LOCK();
  92         result = getlogin_basic(&status);
  93         if (status == 0) {
  94                 if ((len = strlen(result) + 1) > namelen)
  95                         status = ERANGE;
  96                 else
  97                         strncpy(logname, result, len);
  98         }
  99         THREAD_UNLOCK();
 100         return (status);
 101 }